1. Field of the Invention
The present invention generally relates to controlling image information and more particularly relates to an image information control apparatus, an image information control system, a printer driver, an image information method, a computer program using the method, and a recording medium for converting data from an application program to a printer command corresponding to an image forming apparatus.
2. Description of the Background Art
A printer system generally includes a host computer and a printer device connected to the host computer. A printer driver is typically included in the host computer for converting print data generated by an application program of the host computer to a print command of a printer language. The converted data can be compressed and then sent from the host computer to the printer.
For example, Japanese Laid-Open patent Publication No. 2001-2882482 (the entire contents of which are hereby incorporated herein by reference) describes a technology whereby an application program sends bit map data to a printer driver, which stores the bit map data in a buffer memory. Information that is necessary for deciding on a compression technique is also collected, and a user of the system selects a compression technique to be applied to the stored bit map data. The selected compression technique is then applied to compress the bit map data line by line, and the compressed data is sent to the printer for printing. However, the technology described in patent document JP2001-282482 has a problem in that line by line compression is slow, and a single compression technique may not provide optimum print quality for all lines of the bit map data.
Japanese Laid-Open patent Publication No. 2001-306275 (the entire contents of which are hereby incorporated herein by reference) describes another technology that divides a page of image data into bands including a plurality of lines each. The bands are then compressed using a compression technology selected by the user, and the compressed bands are sent to the printer for printing. While this band technology provides improved efficiency in compression, a boundary between bands is difficult to reproduce at the printer with accuracy. To reduce this problem, each band can include bit map data that overlaps with bit map data of an adjacent band in order to provide redundancy for accurate reproduction of data at the boundaries. This leads to complexity and slow print reproduction, as the overlapping data must be removed by the printer as the printer reproduces the data. Moreover, as with the technology described above, the use of the same compression technique for all bands of print data may lead to poor quality printing for portions of the page.
Finally, Japanese Laid-Open patent Publication No. 2001-114778 (the entire contents of which are hereby incorporated herein by reference) describes a printer apparatus that automatically selects a compression technique that has the lowest feasible compression rate from a group of compression techniques, that can compress image data. While this technique provides improvements in print quality, low compression rates cause slow printing. Moreover, as with the techniques described above, use of a single compression technique for the entire page of print data may lead to poor quality printing for portions of the page.